Reflex unit



`P.asaaaug.fi1,i942 I 2,292,715 REFLEX Umar James I.. Peden, Corning, N.V Y.,

assignor to Corning Glass Works, Corning, N. Y., a corporation of New York Application January 27, 193s, serial No. 253,179 romans. (ci. ss-sz),

This invention relates to reflex' signals ofthe autocollimating type and more particularly to a signal construction in which thereflecting surface is located4 protected from exposure to the atmosphere.

Hitherto large numbers of reflex units have been manufactured by molding a solid body of proper configuration from transparentmaterial and providing a mirror surfaceon one end thereof. -Manufacturers of these products have gone to great lengths to protect the reflecting surface, pitches, lacquers and other protecting coatings within the body of the signal and I being liberally applied and, in many instances,

metal shells being applied to protect the adherent coating from mechanical abrasion and maintain it in position.

The object ofthe present invention is a reflex unit in which the reflecting surface is eifectually and permanently protected against atmospheric Vattack and mechanical abrasion without the-use of auxiliary devices. Y

` This object may be attained, within the contemplation of. this invention, in having the reflecting surface located wholly in the body of the unit which may be hermetically scaled by convenient means to prevent ac cess oi-atmospheric agents to the reflecting surface. Such a unit may be hollow and carry the i reflecting material on a suitably contoured inner surface,'or it may include a separate member a reflex unit.

with- "surface is reflected back l and-has'a generally concave body portionl extending into shell .i ll. The position of the con- I6 is determined by a shoulder cave end of body IB formed on the` inside of shell l0, which shoulder the end of body I6 abnts. The lens I2 in? cludes a convex outer face' 2|! which intercepts impinging light rays over arelatively wide angle ,of incidence and aninner convex surfacel 22 of such radius as to focus a substantial portion of the light intercepted by surface' 20 onto thconcave inner surface 24 of body I6. This surface is provided with a reflecting coating which may preferably be metal film deposited in any well known manner. The light impinging on this onto thelens I2 from which it isv projected back toward the source in the usual manner.` t

sealed within the unit and having one or more reflecting surfaces of proper contour- These and other features of the invention will be readily apparent from the accompanying drawing in which:

Fig. 1 is an end view of a single ended reflex unit; Y

. Fig. 2 is a longitudinal section on line 2-2 of Fig. Sais a side elevation, partly in section, of

' a'. double ended reflex unitof similar design;

Fis; 4 is an elevation of a ing to the present, invention; Fig. 5 is a partial Vsection reflex lpanel accordtaken on line 5-5 of Fig'. 4; and

Fig. 6 isa partial transversesection of a modi" glass,

As win te readny observed, the above describedv construction places the vreflecting portion 'of thereflex unit ventirely within the ,body of the unit Where it is mechanically protected by the wallsv of the unit itself. To assemble the parts into a single, unitary structure, a hermetic -seal is effected between the cup Il and shell line of joinder 26. If the unit is formed from the parts may be heated" throughout toa relatively 'high which will not harm the reflecting film-after which the parts may be locally heated to a higher temperature along their line of joinder to seal them together. As an alternative, a lower melting point glass may be'placed in the line of joinder either in powdered orwafer form, and

the parts heated sufiiciently to fuse this material and seal the parts together. In the case of units formed from organic materials, such as the methyl methacrylate resins, organic solvents or cements of a comparable composition may be used. `Such cements and other organic sealing material'may also be used to unite glass, but suchseals are more subject to deterioration and atmospheric attack than'the glass and result in a less satisfactory article as a whole;

The structure shown in section in Fig. 3 dif- -fers from that of Figs. 1 and 2 in that it coinbines the functions of two separate units and fled form of reflex panel according tothe present invention.

Referring tol the; drawingin more detaiL-the reflex button unit shown in Figs. land 2 may be formed of glass or.` other lensportion` lI2 formed thereof. ,-'Acup member is formed toengage theopen lend of the |4501' the same material translucent material and consists of a generally tubular shell I0 having a.

integrally in yoneend will accept-and reflectl back light from each of two oppositely disposed faces. Inthis structure, two .complementary parts each composed of a shell 28 and lens 30 completely enclose a button 32 having -oppositely disposed concave surfaces 34 which arefsilvered or otherwise rendered reflecting.- The position of the. concave surfaces 3l with respect-to the lenses 30 is determined vshell '55 by shoulders 36 formed in thershells 28 which l0 along their temperature in an atmosphere bear against the rim of button az in assembled relation; Shells 28 may be sealed along their abutting edges by the same methods employed `with respect to the structure of Figs. 1 and 2.v

Figs. 4 ad'5 illustrate a somewhat different form ofV doublet reflex unit. In this form of the invention, the exterior surfaces .48 are flat and the lenses 42 for collecting and focusingincident light on the reflecting surfaces are formed on interior surfaces of the unit. This general form of optical structure isy disclosed in the patentto H. P. Gage No. 2,009,769, issued July 30, 1935.. .In the present structure, the outer shell of the unit vis fornied from a pair of complemental saucer shaped members consisting of a face plate 48 bearing lenses l42, an. upstanding sidewall 46 extending about the periphery of the plate and an outwardly flaring rim 48 coextensive with the wall 46. The

'reflecting portion of the illustrated construction consists of a pair of disc shaped members l50 bearing lenses 42 and rendered reiiective in any suitable manner on adjacentopposed faces 44. 'Ihese discsterminate in low, complementary flanges 52 extending vabout their peripheries whichpwhen placed in abutting relation, slightly separate the adjacent surfaces 44. To properly locate the lenses 42 on the respective parts, a

lug i4 is molded into the periphery of each disc 5l and a corresponding notch 56 is formed in the wall and rim of the outer member. y

In the disclosed structure, discs 58 are silvered or otherwise rendered reflecting on their surfaces 44, assembled with their respective'lugs 54 in.

alignment and fused or otherwise hermetically sealed together about their peripheriea "The y iduring the assembly operation such as band 62 in Fig. 6 or may be formed from a number of preformed metal parts soldered together after assembly. Such an arrangement isshown at 58 in FIS. 5.

Various modications of the structure shown in Figs. 4 and 5 are contemplated within the scope of the invention. For' example, as shown in Fig. 6 the diameter of discs 58 may be substan-4 tially equal to that of outer members 40 so that they extend between the rims 48 and into contact with the clamp 82.` Furthermore, when the parts are formed from organic substances, the entire structure may be held together 'with suitable cements and the clamp 58 either eliminated or replaced with a band of cellulosic'or other organic material cemented in position. In each of these modifications, the basic .feature of the invention remains unchanged for the reflecting surface is so located as to be completely enclosed by parts of the body of the unit, which parts are vhermetically sealed together to eliminate all possibility of deterioration of the reflecting surface from atmospheric attack or from mechanical abrasion. Accordingly, the present invention is not to be confined solely to the forms illustrated 10 herein, but is to be limited solely by the scope of the appended claims. What is claimed is: l. An autocollimating unit comprising a pair 'of complementary pressed glass members'adapted to form a hollow body, lenses formed in the oppositely disposed faces `of said members, and a separate glass member. accurately 'positioned within said body midway of said faces, said member being formed vwith a plurality of accurately con- 0 toured surfaces, each bearing a reflecting coating adapted to receive and reflect back light rays transmitted thereto through said lenses, said vmirror surfaces being so. contoured and positioned as to include the points at which light rays entering the unit are brought to a focus.

2. An autocollimating unit comprising a of complementary pressed glass members adapted.

to form a hollow body, lenses formed in the oppo` sitely disposed faces of said members, and a separate glass member accurately positioned within said body midway of said faces and in engagement with 'cireumferentlally disposed locating'shoulders therein, saidl member being fo'rmed with a pluralityof'l accurately contoured surfaces and bearing a pair of reflecting coatings adapted to receive and reflect baclr light rays transmitted thereto through said lenses, said reflecting coat' ings being located at approximately the points -where said rays come to a focus, said comple- 40' mental. glass members being joined together along their abutting edges to form a sealed hollow 3. An autocollimating unit comprising complemental glass parts joined together to form a hol- 5 low glass housing, lens units molded in the walls of said glass parts in oppositely disposed relation and a sealed hollow glass member positioned between lsaid glass parts and accurately located with respect to said lens units and carrying on its o inner surface mirror coatings so located as tol reflect incident'light focused thereon by said lensv units.A

4. An autocollimating unit comprising complemental glass parte Joined together to form a hollow glass housing, lens umts molded in the walls of said glass parts in oppositelydisposed relation4 and a sealed hollow glass member enclosed in said housing and accurately located with respect to -said lens units 'and carrying on its inner surface mirrorl coatings so located as to reflect incident light focused thereon by said lens units.

` JAMES L. PEDEN. 

